A Novel ZIF-9-67Membrane By Mixed-Linker Synthesis For Efficient CO₂Separation

To date, great efforts are being put to find the practical applications of metal-organic frameworks (MOFs). Gas separation may be one of the most promising areas, where membrane-based separation is considered to be energy efficient and requires lower investment cost in many industrial-scale processes compared to the competing technologies, such as pressure swing adsorption and cryogenic distillation. Although MOF membranes have shown promises for gas separation, the controllable modification of its structure and functionality still remains a challenge. Recently, a new strategy is proposed that controlling framework porosity and functionality by mixed-linker synthesis, which may result in hybrid MOFs and the microstructure can be finely modulated by a combination of different ligands in differing relative quantities. On the other hand, industrial gas mixtures usually contain several gases, and thus an ideal membrane for CO2capture should be selective or less selective for CO2over all the other gases, with high selectivity and permeance. However, few of the existed MOF membranes can meet these demands.In this work, we prepared a novel hybrid ZIF membrane by performing mixed-linker synthesis to meet the demands. Compared to the existed MOF membranes, the newly prepared hybrid ZIF membrane is less selective for CO2over H2, CH4, CO and N2with good selectivity and high permeance of H2, CH4, CO and N2; this makes the membrane is very attractive that may find potential applications in CO2capture from industrial mixtures containing these gases.